Location:
North Georgia USA Zone 7b
Your in the ballpark here. Most commercial screened bottom boards are too small for an adult beetle to easily fall through. Might be able to crawl through on the diagonal, but that is not what you want. The scrounged screen I recently used is #6 mesh, .166 minus the wire diameter of .028 so .138 opening. Nothing scientific just using what I had that is close to what is needed.
Oh, welcome to Beesource!
Oh, welcome to Beesource!